Envelope tracking direct current-direct current (DC-DC) converters or envelope tracking modulators perform envelope tracking of signals to be transmitted, e.g., a baseband signal or a radio frequency (RF) signal input to power amplifier (PA) circuitry, and provide a variable power supply voltage to the PA circuitry according to the tracked envelope in order to increase PA efficiency and optimize PA power consumption, e.g., reduce the PA current draw. Envelope tracking facilitates continuously adjusting the PA power supply voltage to operate the PA circuitry at or close to peak efficiency for the given instantaneous output power requirements.